Top Tier Gas – Medicine for Your Engine

When you fill up your car with gas, what’s the main deciding factor between one brand and another? If you’re like most people, it’s price. Perhaps you’re even willing to drive out of your way to save a few pennies on the gallon. But could this cheaper fuel be poisoning your car, potentially leading to costly repairs and even damaging its resale value? Many automotive experts recommend using top tier gas to enhance a car’s performance and potentially reduce the risk of engine damage. Why?

What is top tier gas?

Top tier gasoline may help reduce the build-up of ‘gunk’ in the engine which comes from impurities in gas. These are broken down by adding high levels of detergents to the fuel. Top tier is also free of metallic additives, improving its quality. It is usually slightly more expensive than regular fuel, but only by a few cents per gallon. It was developed to protect the engines of cars with fuel injection technology. During the 80s and early 90s car manufacturers were reporting that the engines of cars with direct fuel injection were getting clogged with gunky build-ups, originating from impurities in gasoline. As a result, the Environmental Protection Agency (EPA) started regulating minimum levels of detergent that need to be present in gas to break down impurities, with the idea of improving fuel quality. Unfortunately, some suppliers reduced the amount of detergent in their gasoline to the specified minimum, reducing the overall quality of fuel available instead of increasing it. In the early nineties some of the world’s biggest auto manufacturers including Audi, BMW, General Motors, Mercedes Benz, Volkswagen, Honda and Toyota set higher benchmarks for top tier fuel. In order to brand their fuel as top tier gas, retailers must ensure that is has two to three times more detergent than the EPA minimum, which combats gunk build-up, and is free of metallic impurities which damage vehicle’s emission-control systems.

Is it different to premium fuel?

Yes. Top tier fuel is different from high performance premium fuel, which has higher octane levels. Top tier octane levels are the same as regular fuel.

Why would I use top tier fuel?

There is some controversy within the auto industry about whether top tier gas is worth the extra money, with some critics labelling it as a marketing ploy to make more money for fuel suppliers. However, numerous automotive experts suggest using top tier fuel, even if not for every tank. The main reasons they recommend it is to help avoid:

Increased deposits on fuel injectors and intake valves

Consequent misfiring spark plugs and reduced performance

Reduced emission efficiency

Repair bills of up to $1000 for a cylinder-head rebuild

If you have a fuel injection vehicle that needs repairs as a result of excess deposits, this could affect the resale value of your car. Some people prefer to use fuel-system cleaning products as they can be cheaper than buying top tier gas regularly, but high levels of these products have the potential to damage catalytic converters. You don’t need to use top tier gas in every tank to get the benefits either, as its unique formulation means that one tank can remove the residue from several tanks of regular fuel. The detergents bind to injectors and valves, protecting against further build-up too.

Where can I find top tier fuel?

You might already be using it without realizing, as 40% of all the gas sold in the United States is top tier. Top tier is sold at gas stations across the country, including major companies like BP, Chevron, Texaco, Costco and Exxon. You can check the top tier site for details of all retailers. Use our free CARFAX records check to see how many service records a used car has – this could highlight problems created by gunk build up among many others. Or see the service records for free on any CARFAX listed used cars. What do you think? Do you use top tier fuel or not, and why?

Octane is added to eliminate engine knocks. That’s it. If your engine doesn’t knock with 87 octane, then anything higher is a waste of money. Only high performance engines with high compression ratios need higher octane.

The article states: During the 80s and early 90s car manufacturers were reporting that the engines of cars with direct fuel injection were getting clogged with gunky build-ups . . .

This is untrue. We did not have direct fuel injection engines until about 2008 or possibly a bit earlier. Fuel injection started to come on during the late 80’s but that was port fuel injection which is largely different from direct injection and the problem was not that then engine was “clogged with gunky build-ups”. More specifically, the injectors were getting clogged. This is not much of a problem any more but direct injection engines are having severe problems with carbonizing in the intake ports because no fuel passes through them allowing the fuel detergents to keep the port clean.

CARFAX Vehicle History Reports are based on information supplied to CARFAX. CARFAX does not have the complete history of every vehicle. Use the CARFAX search as one important tool, along with a vehicle inspection and test drive, to make a better decision about your next used car.